# coding:UTF-8
# 在window下 想展示多进程 是不能使用fork()的函数，需要另一个函数库
from multiprocessing import Process
from multiprocessing import Pool
import os,time,random

# 子进程要执行的代码
def run_proc(name):
    print('Run child process %s (%s)...' % (name, os.getpid()))

# if __name__=='__main__':
#     print('Parent process %s.' % os.getpid())
#     p = Process(target=run_proc, args=('test',))
#     print('Child process will start.')
#     p.start()
#     p.join()
#     print('Child process end.')
#pool 进程池
def long_time_task(name):
    print('Run task %s (%s)..'% (name,os.getpid()))
    start=time.time()
    time.sleep(random.random()*3)
    end =time.time()
    print ('Task %s runs %0.2f seconds'% (name,end-start))


if __name__=='__main__':
    print ('partent process %s '% os.getpid())
    p=Pool(4)
    for i in range(5):
        p.apply_async(long_time_task,args=(i,))
    print ('Waiting for all subprocesses done...')
    p.close()
    p.join()
    print('All subprocess done')

